Utilizing lippmann photographs.



PATENTED JUNE 16, 1908.

A. KHLER & J. LEHMA ZING LIPPMANN PHOTOGRAPHS.

UTILI APPLICATION FILED SEPT. 3,1907.

UNITED STATES PATENT OFFICE.

AUGUST KHLER AND JOHANNES LEHMANN, OF JENA, GERMANY, ASSIGNORS T() THE FIRM OF CARL ZEISS, OF JENA, GERMANY.

UTILIZIN G LIPPMAN N PHOTOGRAPHS.

N o. 890,863. Specification of Letters Patent. Patented June 16, 1908. l

Application led September 3, 1907. Serial No. 391,098.

To all whomz't may concern: lmanner, the entrance pupil has to be ar- Be it known that we, AUGUST KHLER, ranged in thefocal )lane ofthe illuminating doctor of philosophy, and JOHANNES LEH- system. The principal rays proceeding from MANN, doctor of philosophy, citizens of the t e center of tie pupil in that case impinge German Empire, and residing at 'Carl Zeiss upon the hotograph parallel to one another. G0 strasse, Jena, in the Grand Duchy of Saxet In or er to prevent the catadioptric Weimar, Germany, have invented a new and ,l Images of the entrance pupil, which are prouseful Improvement in Utilizin Lippmann duced by the lens surfaces, from being pro- Photographs, of which the fo lowing is a jected upon the dioptric image of the photospecification. graph, t e axis of the reproducing lens sys- 65 The invention consists in an improved aptem may be arranged on one side of the phopliance for reproducing Lippmann phototograph, vbut always erpendicular to it. graphs, under which are to be understood all The lens system is. 1n t iat case used eccenphotographs, which are produced` by statrically. If this system consist of a single tionary waves. Photo raphs of this kind plano-convex piece of a lens, it may be cecan be only re roduce with regularl reniented upon the photograph as a cover flected light, i a rendering of the o ject glass. It stands then at the saine time in photographed be intended to be as true in I the lace of the wedge-shaped cover glass, color as possible. As a method for such re- I whici 1s usually supplied in the case of production Lippmanns-own suggestion only Lippmann hotograp s to remove the disis known, according to which light is made f turbing sur ace reflection. tofall in an inclineddirection upon the photo- Two appliances for the production of a graph and an image of it to be projected with virtual image can be combined to form a the assistance of regularly refiected rays double apparatus for viewing two identical through a collective lens or a collective lens or two stereoscopic pictures. The ap ara- 0 s stem, a virtual image, if it is to be viewed tus designed for a single picture can, owdirect, a real one, if it is'to be visible through l ever, also be arranged so as to use both eyes. the means of a rejection screen. Two Two entrance pupils are then best arranged drawbacks are inlierent in this method. for the light, one on the left for the entrance Firstly, in consequence of the relatively great of the rays which are to be reflected from the 2.5 angles of incidence the colors of the reflected photogra l1 into the right eye, and alright rays undergo a transition towards the violet one for ight which' after reflection at the end of the spectrum. Secondly, the posil photograph is to render the virtual image tion of the photograph deviates by the angle visible to the left eye. of incidence from the position at right angles The arrangement for projecting Lippso to the axis of the reproducing system, so that mann photogra hs by producing a real image the virtual image 1s seen distorted and the in the plane ofp a projection screen in comreal image on a projection screen at right parison to an arrangement for copying'such angles to the axis is likewise distorted and photographs to any scale shows no other only a pears sharp in part. 'undainental difference, than that in the 95 In t e applliance according to the present latter case the screen is re laced by a plate invention t ese drawbacks are avoided. sensitive to light, adapte( to Lip'pinanifs Its principal feature is, that the axis of the reoriginal exposures, in a suitable dark slide. producing lens systemcstands erpendicular In working with such copying apparatus li). Then this more particular attention, than in mere-ly 10o ens system or at least part of it may be loviewing Lippmann liotographs and in proatcd adjacent to the hotograph to serve jecting them, shouldp be paid that, for jlluni'iimultanoously as an il uminating lens s snation, light be used as identical as possible ein. Thus the angle of incidence, un( er in composition to that which in the original hich the illuminating ra s meet the photoexposure the object was illuminatedby.

n the annexed drawing: Figure 1 is a diae entrance pupil near the axis of the ens grammatic plan view of an apparatus for pro- Idueing a virtual image of a Lippmann photo- In order that light may imp inge on the graph to be viewed with one eye.v Fig. 2 is hole surface of the photograph inauniform a agranunatic view of an apparatus for image b of the entrance (pu- O- d, in as far as the picture-film reflects like a lane mirror, at the osition of the eye e. he reproducing pencils produce simultaneously a virtual image d1 of the photograph d behind the hinder surface of the photograph. There are no means rovided in this simple example to abolish the catadioptric images ofthe entrance pupil, the axis of the lense passing right across the photograph d; rlhe zitter is provided only with a plano-parallel cover glass d".

in the arrangement of Fig. 2 presenting a real image cl2, the whole reproducing system, consisting in this case of two lenses f and g, is also madeuseof as an illuminating system. he axis of the system lies, however, at the margin of the photograph, so that merely a portion of the lens f need be employed. l`his portion is made plano-convex and cemented to thephotograph as a cover glass.'

rThe entrance pupil lies inthe plane of the mirror h.

"he arrangement according to Fig. 3 differs from that according to Fig. 2 in that only the part t' of the reproducing system near the ihotograph takes part in the illumination but not the half lens k. The photograph is besides provided with a wedge-shaped cover glass d3, near to which the lens i lies with a sloping plane surface in such a manner, that only a thin plano-parallel stratum of air is between both surfaces so that hardly any influence is exerted on the path of the rays by this stratum, this path being essentially the saine as in Fig. 2, while, however, other photogra hs with wedge-shaped cover glass can readi y be interchanged.

'l he apparatus in Figs. 4 and 5 produces a virtual image with a single lens l, and it renders viewing with both eyes possible. mirror m can be set, so that it refiects light i rom the sky through the openings n and 0, the images nl and o1 of which as projected by the reflecting prisms and 1, represent the with a photograph entrance pupils and he in the Ifocal plane of senese the lens l. As the entrance pupil nl is as distant from the vertical plane through the axis of the lens Z as the e e r, the position of which is determined by t e mask t designed to fit the face, and the pupil o1 as distant from this lane as the eye s, through the combine action of this lens and the picture-film of the photograph d, nl is reproduced at the position of the eye r, and o1 at the position of the eye s. To each eye by this means the virtual image d1 will be visible as in the monocular arrangement according to Fig. 1. The photograph d and the wedge-sha ed cover glass d3 are together placed in a s ide or photograph holder u.

W e claim:

1. In an appliance for reproducing Lippmann photographs by means of reflecte light the combination with a photograph holder of a lens system, the axis of which is perpendicular to the plane of the photograph.

2. In an appliance for reproducing Lippmann photographs by meansv of reflected light t e comblnation with a photograph holder of a lens system, the axis of which'is per endicular to the plane of the photogra h an( a portion of which is adjacent to t e photograph to serve as the illuminating lens system.

3. ln an appliance for reproducing Lippmann lphotographs by means of reflected light lt e combination with a photograph holder of a lens system, the axis of which is perpendicular to the plane of the photograph and an entrance u il arranged 'approximately iii the foca piane of the said. system.

e. in a binocular a pliance for producing a virtual image ofanppinann photograp by means of reflected light, the combination holder of a lens system, the axis of which `is perpendicular to the plane of the photograph, a iei't and a right entrance pupil and means for locating the eyes, the pu ils and the eyes lying approximately in the ibcal plane of the ens system and the distance from the vertical plane through the axis of the said system being approximately the same for the left eye and t e right entrance pupil and for the right eye and the left entrance pupil.

AUGUST KHLER. JOHANNES LEHMANN.

Witnesses PAUL KRUGER, Fnrrz SANDER. 

